Group 13 based Lewis acids having three fluorinated aryl substituents are known to be capable of activating transition metal compounds into olefin polymerization catalysts. Trisperfluorophenylborane is demonstrated in EP 0 425 697 and EP 0 520 732 to be capable of abstracting a ligand for cyclopentadienyl derivatives of transition metals while providing a stabilizing, compatible noncoordinating anion. See also, Marks, et al, J. Am. Chem. Soc. 1991, 113, 3623-3625. The term "noncoordinating anion" is now accepted terminology in the field of olefin polymerization, both by coordination or insertion polymerization and carbocationic polymerization. See, for example, EP 0 277 004, U.S. Pat. No. 5,198,401, and Baird, Michael C., et al, J. Am. Chem. Soc. 1994, 116, 6435-6436, and U.S. Pat. No. 5,668,324. The noncoordinating anions are described to function as electronic stabilizing cocatalysts, or counterions, for essentially cationic metallocene complexes which are active for olefin polymerization. The term noncoordinating anion as used here applies both to truly noncoordinating anions and coordinating anions that are at most weakly coordinated to the cationic complex so as to be labile to replacement by olefinically or acetylenically unsaturated monomers at the insertion site. The synthesis of Group 13-based compounds derived from trisperfluorophenylborane are described in EP 0 694 548. These compounds are said to be represented by the formula M(C.sub.6 F.sub.5).sub.3 and are prepared by reacting the trisperfluorophenylborane with dialkyl or trialkyl Group 13-based compounds at a molar ratio of "basically 1:1" so as to avoid mixed products, those including the type represented by the formula M(C.sub.6 F.sub.5).sub.n R.sub.3-n, where n=1 or 2. Utility for trisaryl aluminum compounds in Ziegler-Natta olefin polymerization is suggested.
General synthetic work includes a description of the preparation of compounds said to be new tris(fluoroaryl)boranes in a paper by D. Naumann, and others, "Darstellung und Eigenshaften neuer Tris(fluoraryl)borane", in Zeitshrift fur anorganishe und allecemeine Chemie, 618 (1992) 74-76. The authors include reference to the compound tris(tetrafluoroarylpyridyl)borane.
Supported non-coordinating anions derived from trisperfluorophenyl boron are described in U.S. Pat. No. 5,427,991. Trisperfluorophenyl boron is shown to be capable of reacting with coupling groups bound to silica through hydroxyl groups to form support bound anionic activators capable of activating transition metal catalyst compounds by protonation. U.S. Pat. No. 5,643,847 discusses the reaction of Group 13 Lewis acid compounds with metal oxides such as silica. It illustrates the reaction of trisperfluorophenyl boron with silanol groups (the hydroxyl groups of silicon) so as to prepare bound anions capable of protonating transition metal organometallic catalyst compounds and forming catalytically active cations counter-balanced by the bound anions.
Immobilized Lewis acid catalysts suitable for carbocationic polymerization are described in U.S. Pat. No. 5,288,677. The Group III A Lewis acids of the invention are said to have the general formula R.sub.n MX.sub.3-n where M is a Group III A metal, r is a monovalent hydrocarbon radical consisting of C.sub.1 to C.sub.12 alkyl, aryl, alkylaryl, arylalkyl and cycloalkyl radicals, n=0-3, and X is halogen. Listed Lewis acids include aluminum trichloride, trialkyl aluminums, and alkylaluminum halides. Immobilization is accomplished by reacting the invention Lewis acids with hydroxyl, halide, amine, alkoxy, secondary alkyl amines, and others, where the groups are structurally incorporated in a polymeric chain. James C. W. Chien, Jour. Poly. Sci.: Pt A: Poly. Chem, Vol. 29, 1603-1607 (1991), has described the olefin polymerization utility of methylalumoxane (MAO) reacted with SiO.sub.2 and zirconocenes. He proposes a covalent bonding of the aluminum atom to the silica through an oxygen atom in surface hyroxyl groups.
In view of the above there is a continuing need for activating cocatalyst compounds both to improve industrial economics and to provide simpler methods of synthesis and preparation of suitable activating compounds for ionic catalyst systems. Additionally, improvements in gas phase and slurry polymerization of olefins, where supported catalysts are typically used, are sought so as to meet the demanding criteria of industrial processes. The complexities of the polymerization media of industrial processes can result in widely varying product properties of the polymers prepared and the polymer particles formed in the reactors from which the polymerization medium must be removed for final product preparation.